In recent years, TFT-LCD liquid crystal panels has been widely used. Liquid crystal displays are used in various products, such as televisions, cell phones, computers, digital cameras and so on. Liquid crystal displays have deeply entered into each field of our life. At present, the most common one is the TFT (Thin Film Transistor) type liquid crystal display which realizes independent and precise control of each pixel through an active switch, thus can realize subtler display effect compared with passive drive (commonly known as Pseudo-color) in the past. The TFT-LCD process is divided into three segments: an Array process, a Cell process, and a Module Assembly process. In the Cell process, impurities such as stubborn cullet, residual adhesive, oil stain, residual liquid crystal and the like are always left on the surface of a substrate after liquid crystal filling, end sealing, cutting and edge grinding, and such impurities must be cleaned clearly before attaching polarizers. If the residual impurities can't be effectively removed from the surface of the substrate, undesirable phenomenon will occur, such as short circuit between metal layers, falling-off or residual in large areas of the metal layer and the like, which will finally influence various electrical properties of products. At early stage, the impurities were manually removed by wiping with a dust-free cloth, scraping with blades and the like, which have drawbacks of low efficiency and easily cause scratches to the panel, thereby it cannot satisfy production requirement of production line at high-tech age.
At present, there are mainly two technology methods for cleaning the panel prior to attaching polarizers in the Cell process of liquid crystal panel. In a first method, the panel is cleaned by brush cleaning, which removes impurities by taking advantage of friction between a brush and a glass substrate. Brush cleaning can easily remove stubborn dirt and stains from the glass substrate, and has a good effect for removing inorganic particles which are larger than 5 um and tightly adsorbed on the glass substrate, but has limited ability for removing small granule impurities, organic residual adhesives, mark calligraphy and the like. The brush must be kept clean when in use, thus preventing recontamination of the glass substrate due to the dirt on the brush. Generally, a brush has a short service life, and will lose hair after using for a period of time, thus requiring regular replacement. In a second method, the panel is cleaned by grinding with a textile polishing cloth. The textile polishing cloth is a coated grinding consumable, which has a coating layer having grinding ability on a surface thereof, wherein the coating layer forms pits evenly distributed along the warp and weft of the textile cloth. During in use, the coating layer having grinding ability contacts the glass substrate, and can well remove the impurities on the surface of the glass substrate at a certain pressure. The pits on the surface of the textile polishing cloth can contain the impurities and grinding chips and the like which are cleaned off, thus can effectively avoid scratching the panel to some extent. However, since the grinding coating layer is prepared by a coating method, the distribution of the grinding layer in a cloth base is random and uneven, which results in instability of cleaning ability. Moreover, the pits on the surface of the textile polishing cloth have a limited ability for containing the grinding chips, and will result in scratch of the glass substrate once beyond the ability. Generally, the textile polishing cloth is a single-layer coating cloth, which only has one life and has a short service life.